prosthodontics lab book

Question 1

What are the stages of full veneer crown prep?

Answer 1

Occlusal, Buccal, Lingual, Mesial, Distal.

Question 2

What are the main aims in full veneer crown prep?

Answer 2

Functional cusp bevel (structural durability), axial reduction (retention/resistance), planar occlusal reduction (durability).

Question 3

How do you assess occlusal reduction?

Answer 3

Use a putty index, check clearance from opposing tooth, maintain occlusal morphology, achieve 1mm clearance, 1.5mm at functional cusp bevel.

Question 4

What is the axial reduction aim for full crowns?

Answer 4

0.5mm chamfer, 1mm supragingival, no undercuts, 12° taper, smooth transitions buccal to lingual.

Question 5

What features are critical for an anterior metal ceramic crown?

Answer 5

Chamfer, wing, incisal notch, shoulder, axial reduction.

Question 6

What are the main principles of preparation? ACC

Answer 6

Retention, resistance, marginal integrity, structural durability, no undercuts, conservation.

Question 7

How much incisal reduction is needed? ACC

Answer 7

2mm

Question 8

What is the labial shoulder dimension? ACC

Answer 8

1.2–1.5mm.

Question 9

Palatal margin dimension? ACC

Answer 9

0.5mm chamfer.

Question 10

Why do we need temporary crowns?

Answer 10

Protect dentine, aesthetics, function, prevent drifting, allow healing, diagnostic purposes.

Question 11

What are direct techniques for temporary crowns?

Answer 11

Custom made with putty index, alginate, or vacuum-formed splint.

Question 12

What materials are used in direct temporaries?

Answer 12

Polyvinyl ethyl methacrylate, bis-acryl composite.

Question 13

When making a temporary with a putty index, how long before you remove it from undercuts?

Answer 13

~1 min 15 sec (before fully hard).

Question 14

Where is indirect temporisation done?

Answer 14

In the laboratory or chairside.

Question 15

What materials are used for indirect temporaries?

Answer 15

PMMA resin (with lab pressure curing for strength).

Question 16

What materials are prefabricated temporary crowns made from?

Answer 16

Polycarbonate (anterior), aluminium (posterior), stainless steel (posterior).

Question 17

How do you modify a polycarbonate crown?

Answer 17

Adjust with Soflex disc/acrylic bur, line with Integrity, reseat, trim.

Question 18

Name two temporary cements.

Answer 18

TempBond (Zinc Oxide Eugenol), TempBond NE (Non-Eugenol)

Question 19

What are functions of a provisional bridge?

Answer 19

Aesthetics, pulp protection, function maintenance, stability, diagnostic use.

Question 20

Ideal requirements for a provisional bridge?

Answer 20

Aesthetic, stable, durable, biocompatible, easy to remove

Question 21

Name alternatives to traditional temporaries.

Answer 21

Spot-etch composite, modified Essix retainer, acrylic denture tooth adaptations.

Question 22

What are two retraction methods before impressions?

Answer 22

Retraction cord, astringent retraction paste.

Question 23

What is a fixed-fixed bridge?

Answer 23

Connects abutments at both ends with good retention.

Question 24

What is a cantilever bridge?

Answer 24

Pontic connected at one end only, conservative but limited span

Question 25

What is a fixed-movable bridge?

Answer 25

Rigid connector at fixed end, movable joint at minor retainer.

Question 26

What is the purpose of a surveyor?

Answer 26

To identify undercuts and design paths of insertion for prostheses.

Question 27

What are guide planes?

Answer 27

Parallel surfaces created to limit paths of prosthesis withdrawal.

Question 28

How should you prepare a guide plane?

Answer 28

Stay in enamel, wrap around the tooth, use the side of the shoulder bur.

Question 29

What is an overdenture?

Answer 29

: A denture supported by retained natural teeth or roots.

Question 30

Advantages of overdentures?

Answer 30

Less alveolar bone loss, better retention, improved sensory feedback.

Question 31

Disadvantages of overdentures?

Answer 31

Higher cost, maintenance issues, caries/periodontal risks.

Question 32

Patient requirements for overdentures?

Answer 32

Good OH, low caries risk, suitable teeth with good bone support.

Question 33

Minimum number of overdenture abutments needed?

Answer 33

At least 2.

Question 34

Preferred teeth for overdenture abutments?

Answer 34

Canines > premolars > molars > incisors.

Question 35

Simple dome preparation height?

Answer 35

2–3mm supragingival.

Question 36

Types of trauma leading to tooth loss?

Answer 36

Concussion, subluxation, lateral luxation, intrusive luxation, extrusive luxation, avulsion.

Question 37

Advantages of immediate replacement options?

Answer 37

Speech, aesthetics, function maintained, minimal plaque retention.

Question 38

Two main methods for immediate tooth replacement?

Answer 38

Using patient's own tooth, using acrylic denture tooth + orthodontic wire.

Question 39

Key features of resin-retained bridges?

Answer 39

Minimal/no prep, must remain in enamel, 180° wrap-around.

Question 40

What material is commonly used for onlays?

Answer 40

IPS e.max.

Question 41

What is critical when preparing a cavity for an onlay?

Answer 41

Wide MOD undercut cavity, at least 4mm wide at box sections.

Question 42

What is the ideal taper for crown prep?

Answer 42

6° per wall, 12° total.

Question 43

Why is a functional cusp bevel needed?

Answer 43

To prevent thin casting and fracture.

Question 44

What if you don’t reduce occlusally enough?

Answer 44

Weak crown, poor occlusion.

Question 45

What is the incisal reduction aim for an anterior metal-ceramic crown?

Answer 45

2mm.

Question 46

What is the shape of the labial shoulder margin?

Answer 46

90° shoulder with rounded internal line angles.

Question 47

Why create a wing on anterior crown prep?

Answer 47

To conserve palatal tooth structure.

Question 48

What happens if you remove the putty index too late during direct temporary crown making?

Answer 48

Risk of locking in undercuts and damaging prep.

Question 49

Temporary crown material example for anterior teeth?

Answer 49

Integrity (bis-acryl).

Question 50

Main disadvantage of direct temporary crowns?

Answer 50

Weaker and rougher fit than lab-made.

Question 51

What are indications for a fixed-fixed bridge?

Answer 51

Good abutments, short span, high aesthetic needs.

Question 52

Main indication for a cantilever bridge?

Answer 52

Replacing a single missing tooth.

Question 53

How do you manage differential abutment movement in a bridge?

Answer 53

Use a fixed-movable connector.

Question 54

What is a surveying tool that checks undercuts?

Answer 54

Undercut gauge.

Question 55

What determines path of insertion?

Answer 55

Guide planes.

Question 56

Ideal size of a guide plane?

Answer 56

2–3mm in height, 1/3 buccolingual width.

Question 57

Purpose of guide planes in RPDs?

Answer 57

mprove retention and stability.

Question 58

How are overdenture abutments prepared?

Answer 58

Dome-shaped, supragingival, pulp capped if needed.

Question 59

What attachment system might be added to overdenture abutments?

Answer 59

Stud attachments (e.g., Locator, ERA).

Question 60

Risk of not maintaining overdenture abutments?

Answer 60

Caries, periodontal disease, loss of support.

Question 61

Immediate action for avulsed tooth with closed apex?

Answer 61

Replant ASAP and splint.

Question 62

Immediate action for avulsed tooth with open apex?

Answer 62

Replant and monitor pulpal healing.

Question 63

If replanting delayed >60 mins, what is the outcome?

Answer 63

Ankylosis and root resorption likely.

Question 64

Ideal material for splint wire in immediate replacement?

Answer 64

0.3–0.4mm orthodontic wire.

Question 65

How do you attach acrylic denture tooth in immediate replacement?

Answer 65

Bonded with composite resin.

Question 66

Main disadvantage of resin-retained bridge?

Answer 66

Debonding risk over time.

Question 67

Why should RRB prep remain in enamel?

Answer 67

Better bond strength.

Question 68

What is the minimum wrap-around needed for RRB wing?

Answer 68

180° around abutment tooth.

Question 69

Why is 2mm occlusal clearance needed for e.max onlay?

Answer 69

To prevent fracture.

Question 70

What type of margin is best for e.max onlay?

Answer 70

Butt margin.

Question 71

Why are bevels NOT recommended with e.max onlays?

Answer 71

educes bondable surface area.

Question 72

Crown Prep:

Answer 72

1mm chamfer, 2mm occlusal, 12° taper.

Question 73

Anterior Crown

Answer 73

2mm incisal, 1.2–1.5mm labial shoulder.

Question 74

Temporary Crown

Answer 74

Bis-acryl, remove from undercuts early.

Question 75

Fixed Bridge

Answer 75

Fixed-fixed = rigid both ends.

Question 76

Cantilever

Answer 76

Only one retainer.

Question 77

Surveyor:

Answer 77

Finds path of insertion and undercuts.

Question 78

Guide Planes

Answer 78

Created in enamel, 2-3mm high.

Question 79

Overdentures:

Answer 79

Keep 2 roots minimum.

Question 80

Immediate Replacement

Answer 80

Own tooth or denture tooth + wire

Question 81

Resin-Retained Bridge

Answer 81

Stay in enamel, wrap 180°.

Question 82

Onlay:

Answer 82

Butt margins (90° exit angle).. 2mm occlusal clearance

Question 83

Answer 83

coping and dome shaped